Bat House Forum

[IowaNate]

  This is my first time replacing houses that have been occupied. The houses have had maternity colonies of little brown bats for about ten years. It's now November and the bats have left for the season.

   My concerns are if the bats will take to the new roosts as readily as the old houses. The houses are almost identical to the old ones, but a bit larger (see post of " My new bat house design") They will have plenty of time to "weather" in the elements before the bats arrival next spring.

   Has anyone had good success with replacing previously occupied houses? I consider these houses to be much better than the old ones & I have no choice but to replace them since they are in bad disrepair. I hope the bats see the new houses as an upgrade to their former homes.

[kent borcherding]

If you can mount the new houses back to back with the old houses for at least another year or more will help to encourage the colonies to use the new houses.

Bat have a very strong sense of smell and the new wood smell in the new houses usually causes some of the bats to look for a new site Also by leaving the old houses when the adult females of the colony swarm the boxes with the new pups , the pups homing instinct brings them back to those houses the following year.

If you remove the old houses and place the new the females that leave to a new maternity site , the pups born at the new site will home back to that site the following year. Bats have an unbelieveable homing instinct.

I usually always start with 2 houses at a site and if around 25 females use it for a maternity site I will increase the houses to 4 - 6 houses at that site in the fall after the bats leave. The pups born at the site will home back to it ,and I have the bat houses to accomadate the bats as the number of bats increase at that site.

Seems to work best if I can maintain at least 2 more houses at a site than needed for the capacity of the colony occupying that particular site.

That way if something happens to a house or I replace a house the bats will use one of the extra houses until the colony is comfortable using the new house.

[BatMan]

You could also attempt to smear some guano on the inside of the new houses.

[IowaNate]

 Thank you Kent for your insite! Although I did replace both houses today, there are a few bat houses nearby that others have put up and have held small numbers of bats in the past three years. Granted none are in as good of a location as the houses that I put up (the others are semi-shaded and close to branches) I hope that if some of the bats do relocate temporarily, they will be in some of the houses that are within 200 yards. There is also a Missouri style bat house (2 feet wide, 4 feet long and 2 feet tall...although the chambers are just 12" tall with a large attic space taking up the other 12")  just 100 feet from my houses. It has held a few bats (less than 20) during the 15 years it has been up, but it is only 9 feet from the ground and in an area that only gets about 3 to 4 hours of direct sunlight. The Nature Center had good intentions with this large house, but it has failed to attract many bats due to it low hieght and shaded area. But these houses might be better than nothing if my bats chose to relocate temporarily.

   Should I attach some of the old smelly partitions to the new houses? I can cut some small pieces and attach them to the landing pad and lower parts of the partitions of the new houses. It would definately be a familiar smell if that's what the bats are seeking.

   The Nature Center only allows me to put up a few houses, and mounting the new houses to the back of the old ones would've meant lots of guano on the elevated deck (which is unacceptable). I kind of got "dibs" on the best spots for bat houses on the Center's 210 acre site. I am going to petition to get permission to put up one pole in the marsh habitat, there are two shallow ponds covering one acre on this site. If my petition is accepted, I want the largest house, or back to back houses that two to three people can mount by themselves. I'd like to create a new colony of 400+ bats at the marsh site.

       Below is a general diagram of the site. My current bat houses are designated by a "BH" on the South side of the RED Nature Center. Distance from the Center to the creek is about 100 feet. Distance from the Center to the river is about 200 yards. The PURPLE marsh is about 1/4 mile from the Center. And the marsh is only 200 yards from the river as well. YELLOW indicates areas of low brush and open areas. The ORANGE prairie is native flowers and wild grasses. The GREEN woods are mostly broad-leafed trees consisting of mature maples and oaks. 

[Terry Lobdell]

That is a really good location you have there Nate!

The more bat houses the better...........if they get an infestation of bat bugs they can just leave and go to another house.